Optical fibers are commonly used for delivery of optical beams produced by laser sources such as laser diodes to a work surface or other target. Optical fibers offer many advantages over conventional optical systems used for beam delivery as optical fiber based systems tend to be small, inexpensive, and permit convenient beam delivery even to difficult locations. Optical fibers of many sizes and designs are commercially available, and system designers have many options.
One shortcoming of conventional fiber beam delivery is that the optical beams produced tend to be non-uniform, and often include beam areas in which beam flux (optical power/area) is significantly larger or smaller than an average beam flux. In some cases, non-uniform beams that are input to a fiber delivery system are reproduced at the beam delivery output with substantially the same non-uniformity. In many conventional fiber beam delivery systems, even if uniform beam flux were achieved, slight fiber bendings tend to produce non-uniform beam fluxes or otherwise alter beam flux.
Thus, using conventional fiber delivery systems, beam fluxes tend to be non-uniform and variable. Disclosed herein are representative methods and apparatus for beam delivery that generally tend to produce uniform, stable beam fluxes.